Lease Obligations - Lessee - Lease Assets and Lease Liabilities (Details) - USD ($) $ in Millions	Dec. 31, 2021	Dec. 31, 2020
Leases [Abstract]
Operating lease right-of-use assets	$ 427	$ 423
Finance lease right-of-use assets	145	129
Total right-of-use assets	572	552
Operating lease liabilities	520	527
Finance lease liabilities	149	130
Total lease liabilities	669	657
Operating lease right of use asset, accumulated amortization	198	152
Finance lease right of use asset, accumulated amortization	$ 47	$ 29
Operating lease right-of-use assets [Extensible List]	Other assets	Other assets
Finance lease, right-of-use assets [Extensible List]	Bank premises and equipment	Bank premises and equipment
Operating lease liabilities [Extensible List]	Accrued Liabilities [Member]	Accrued Liabilities [Member]
Finance lease liabilities [Extensible List]	Long-term debt	Long-term debt